When one of the surface panels of a hollow wall member such as a door or the like becomes broken, it is difficult for the average person to repair it. Various devices have been designed and placed on the market for providing a backup surface against which a filler material is packed into the opening. These prior art devices are, however, complex in construction, expensive to manufacture, and difficult to use. It would be desirable, therefore, to provide a backup device which is simple in construction, inexpensive to manufacture and which can be readily used by the average person to repair holes in hollow walled articles.